Over the past few years, research in metrical phonology has witnessed a shift in its main topic of investigation. Originally, attention was focused on the representation of prominence patterns of words (for example, Liberman & Prince 1977; Kiparsky 1979; Selkirk 1980; Hayes 1981), but more recently interest has arisen in several sorts of ‘rhythmic’ stress phenomena in larger domains (Prince 1983; Hayes 1984; Selkirk 1984; Hammond 1984; Giegerich 1985). One way of explaining this shift is by noting that the issue of the treatment of prominence patterns proper seems to have reached a stage where both grid-only (i.e. tree-less) theory and variants of tree-full theories, whether or not they employ grids as well, are capable of explaining the prominence patterns of words (see, for instance, Prince 1983; van der Hulst 1984). In this situation, investigation of rhythmic stress phenomena may offer the possibility of evaluating these theories because, as currently perceived, this area typically deals with the issue of whether metrical tree structure is needed at all, or whether grid structure by itself is capable of explaining rhythmic adjustments: on the one hand, grid-only theory claims that any constituency relevant to rhythmic adjustment is adequately encoded in the grid; on the other, tree theory holds that more detailed, or perhaps different, constituent information is required, as expressed in the metrical tree.